You might need the assistance of a time machine to find a child who is clamoring for a "Mr. Peabody & Sherman" feature film remake.

More than many of Jay Ward's animation creations, the 1950s/1960s cartoons present a high degree of difficulty to stretch into a full-length movie. They were just five minutes long. There was very little character development. And while the cartoons are revered by aging animation fans, they haven't received the rerun love they deserve in recent years.

A series of sound decisions and a few unfortunate ones result in an entertaining-but-forgettable diversion from DreamWorks Animation.

Fans of the original "Peabody's Improbable History" shorts that ran on "The Rocky and Bullwinkle Show" won't be horribly offended. Parents will appreciate the fact that the bodily functions jokes are kept to a minimum. Little kids will enjoy the movie, but they like pretty much everything. (See: "The Smurfs 2")

While the time travel core is intact, there are few retro touches in the remake. Genius dog Mr. Peabody and his adopted son Sherman live in a postmodern penthouse that you would expect from a tech billionaire. The WABAC machine is no longer a charming series of corkscrew wires and lights and vacuum tubes — it's now a spaceship with a high tech hangar that looks like a collaboration between Tony Stark and Batman.

Worst of all, Peabody and Sherman are strapped with a first act full of modern problems. Needing to fill an extra 85 minutes, the writers clumsily explore the characters' therapy needs. Sherman is bullied at school. Both characters say things they regret in the heat of passion. Peabody has trouble saying "I love you."

"Mr. Peabody & Sherman" gets much better when the pair go back to the basics: Traveling in time and offering a helping hand with history. Leonardo da Vinci, King Tut, Marie Antoinette and George Washington all make enjoyable cameos. Scenes in the bowels of a Trojan horse with King Agamemnon provide the most comic value. (Thanks once again to Patrick Warburton, a first-ballot inductee should anyone ever build an Animated Voice Actor Hall of Fame.)

Technically, "Peabody" looks great. The ending is a bit of a letdown — yet another "Avengers"-esque colorful space vacuum threatening to destroy a big city. But director Rob Minkoff, who helped make "The Lion King," ably juggles various characters and conflicts to the tidy finish.

The late Bill Scott seems irreplaceable as the original voice of Peabody, but "Modern Family" star Ty Burrell is a sound choice, conveying intelligence, self-satisfaction and just a hint of warmth. Other than a few sword fights, the majority of the crises throughout the film are solved by intelligence.